I am proposing to do a loft conversion above my first floor flat. This will involve putting in a new staircase which will start from my landing above the existing stairs. As the first stair is sitting on the existing floor, it will put a load on the floor (all be it a small one). Does anyone know if this requires me to provide a “party wall-structure” agreement with the owner (and freeholder)? I have informed them that I am getting planning and building regs approval before starting work. Also, there will be an increased loading on the load bearing walls where the increased floor load will be transmitted down to the foundations. Does this have any involvement with the “Act”.

If you are intending to cut into the party wall for any purpose you will need to serve a party structure notice on your neighbour. The freeholder and any person with an interest in the property (lease of over 12mths) will require notice to be served. You will only need to enter into an Award (agreement) if the adjoining owner(s) dissent from that notice.

I would be happy to give you detailed advise and costs if you need any further help.

I don’t need to cut into the party walls or floors. The addition loading will however be applied to my part of the structure, and down through my existing load-bearing walls/floors to the walls beneath. If I don’t physically cut into any structure (or undermine it) do I assume the extra loading does not come under the party wall act? Obviously the strength of the existing floors and walls were taken into account when the loft conversion was designed.